sctp.local_addr_list is a global address list that is supposed to include all the local addresses. sctp updates this list according to NETDEV_UP/ NETDEV_DOWN notifications. However, if multiple NICs have the same address, the global list would have duplicate addresses. Even if for one NIC, promote secondaries in __inet_del_ifa can also lead to accumulating duplicate addresses. When sctp binds address 'ANY' and creates a connection, it copies all the addresses from global list into asoc's bind addr list, which makes sctp pack the duplicate addresses into INIT/INIT_ACK packets. This patch is to filter the duplicate addresses when copying the addrs from global list in sctp_copy_local_addr_list and unpacking addr_param from cookie in sctp_raw_to_bind_addrs to asoc's bind addr list. Note that we can't filter the duplicate addrs when global address list gets updated, As NETDEV_DOWN event may remove an addr that still exists in another NIC. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>